This invention relates to the separation of grit from liquid sewage, and more particularly to improvements in the ability to remove fine grit of grit selectors of the general type disclosed in U.S. Pat. No. 3,941,698, which is assigned to the same assignee as this invention. Such grit selectors produce a forced vortex with an upward spiral flow that moves settled grit across a transition surface into a grit removal opening while keeping or lifting organics into suspension in the spiral flow until they are discharged into a sewage treatment unit. Such grit selectors were significantly better than the devices which preceded them, and this invention involves modifications which make the subject grit selectors even better.